Boy, do I agree with Larry on this one.
Stepping all the way back to a bicycle would be the eventual result following the logic here. That logic being that once every part known to man has been tried, get a bicycle.
To me those systems are like working on a bicycle. We seldom have any trouble identifying the problems. The problem trying to help on one of these boards is that the testing we would do, just isn't a possibility in the field.
I understand how frustrating it can be to deal with such problems, we are running into such affairs regularly with the new systems. Proper testing is the answer and with the proper tooling and Experience, it gets to be routine.
Bosch Master, ASE Master, L1
33 years MB technician